For the most up to date assembly tutorial, please go here.

This is a step by step guide on how to make an Open Bionics Ada robotic hand. This is derived from the Dextrus robotic hand, by the Open Hand Project. It assumes you have either ordered the Ada robotic hand kit or have access to a 3D printer and are planning to print 3D parts from YouMagine or thingiverse. The list of required 3D printed parts, components and tools are stated below. If you have purchased the Ada kit, you can skip the first step and start straight from step 2.

This hand would provide an excellent research platform for robotics or a test platform for prosthetics research. It has been designed to be easy to build and repair and should be a great project for someone with interests in robotics or prosthetics and wants their very own robotic hand!

This instructable will take you through the assembly of the 3D printed parts, the mounting of the circuit board, and the uploading of test firmware. If you have all of the parts to hand, assembly should take around 1 hour. The assembly of this hand is exactly the same for both a left and right hand, the only difference being in Step 4, mounting the electronics.

Assembly Steps:

  1. Printing and removing support material
  2. Inserting the motors
  3. PCB tray assembly
  4. Mounting the electronics
  5. Attaching the back cover
  6. Uploading the test firmware
  7. Attaching the finger tendons
  8. Hand is complete

Tools required:

  1. M3 Allen key
  2. Tweezers/Needle nose pliers
  3. Scissors
  4. Soldering iron (used for the push inserts)
  5. Micro USB cable
  6. 12V DC power supply

Components required:

  1. Super glue
  2. 9 x M3 bolts (6mm length)
  3. 13 x M3 threaded push inserts
  4. 1m x 0.7mm tendon string
  5. 5 x Firgelli 12V linear actuators (PQ12-30-12-P)
  6. 1 x Open Bionics Almond electronics
  7. 5 x Micro gel fingertip grips

3D printed parts:

  1. Palm
  2. PCB tray upper
  3. PCB tray lower
  4. Back cover


If you enjoyed this tutorial and wish to continue working with us to improve robotic hands, become part of the developer community. If you have any queries or just fancy keeping up with this project, feel free to join us over on our forum http://openbionics.lefora.com.


Ada robotic hand by Open Bionics is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License. Please be aware that the Open Bionics Ada robotic hand is not a medical device.

Step 1: Printing and Removing Support Material

For the most up to date assembly tutorial, please go here.

First off, we'll need to print the 4 main components for the Ada robotic hand, the files can be found on YouMagine or thingiverse.

You will need:

  • 200g Ninjaflex
  • 100g PLA/ABS

3D printed parts:

  • Palm
  • PCB tray upper
  • PCB tray lower
  • Back cover

The palm is to be printed in Ninjaflex, and all of the other components are printed in either PLA or ABS (whichever you feel most comfortable printing with). Note that most of these parts require support to be printed effectively.

For a more detailed guide on printing the Ada hand, visit this tutorial.

The Palm

  1. To print the palm make sure that the part is orientated correctly, so that the wrist and the fingertips are both the bottom most points of the model (pictured)
  2. Our recommended Ninjaflex print settings are as follows
    1. Layer height 0.3 mm
    2. Fill density 45%
    3. Support material
      1. Type: Touching Build Plate
      2. Angle: 30°
      3. Density: 25%
    4. Print speeds
      1. Infill 20mm/s
      2. Outer shell 16mm/s
      3. Inner shell 20mm/s
  3. The print usually takes around 20 hours, but print time may vary depending on your print settings
  4. Once printed, remove the palm from the bed and use pliers to remove the support material from the back and inside of the hand
  5. Be sure to also remove all of the support material in the large motor horn holes and in the back of the motor slots (pictured)
  6. You should also remove any support material inside the tip of thumb, but make sure you don't damage the tendon attachment point on the tip of the thumb

PCB Tray

  1. Print both of the PCB tray components (upper and lower) in PLA (or ABS) so that the flat faces are on the bed
  2. These components do not require any support to be printed, and usually take around 2 hours
  3. These components will be glued together in step 3

Back Cover

  1. Print the back cover with support in PLA (or ABS), and orientated so that the wrist is on the bed and the part is vertical
  2. This part takes around 6 hours to print
  3. Once printed, remove the support from inside the cover and within the cable holes in the wrist

You should now have printed and cleaned up the palm, PCB Tray and back cover, the next step involves inserting the motors into the palm.

<p>Thanks for reminding</p>
<p>I checked your shop for Ada Hand Kit,<a href="http://www.openbionics.com/shop/?category=Kits," rel="nofollow">http://www.openbionics.com/shop/?category=Kits,</a> yet there is no kits.<br> I'd like to purchase the 3D printed hand along with other materials from your shop</p>
<p>We have a kit available now:</p><p><a href="http://www.openbionics.com/shop/ada">http://www.openbionics.com/shop/ada</a></p><p>Thanks!</p>
<p>Thank you !<br>Can you please make an Instructable on how to build the PCB, I kinda got lost using the CAD software.</p>
Hi,<br><br>Thanks for getting in touch with us, we will be offering full kits soon, we'll let you know when they've been released.
<p>can you share the board in &quot;.brd&quot; to eagle software?. Thanks</p>
<p>Hi FelipeG8,</p><p>All of the Almond files and documentation can be downloaded from www.openbionics.com/downloads</p>
<p>Ok, thanks. Now, i will try to make the PCB</p>
<p>Can you please make an Instructable on how to build the PCB Almond board ?</p>
<p>Excellent job </p>
<p>The graphics are amazingly well done. :) Overall, nice concept and design! </p>
totally want one with more articulation man!
Great idea mchau2!<br><br>Why not join our developer community and suggest it in the forums?<br><br>www.openbionics.com/developer<br><br>Or better yet work on it yourself. ;)
i would love to work on sth like this!! but i lack a printer and money for online shopping... all i can do is simply modeling...
<p>Simply modeling would be great. The idea behind the forum is that it could link you to someone with a printer! If we like your work enough it could even be incorporated into future versions; fully crediting you of course. </p>
just sign up man!
<p>Wow, this is really amazing and detailed. Thanks for posting and sharing your knowledge!</p>

About This Instructable




Bio: Open Bionics is an open source robotics company 3D printing low-cost robotic hands for amputees. Join our developer forum! http://www.openbionics.com/developer/ Talk ... More »
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